Nerve cell migration after birth may explain infant brain’s flexibility Frontal lobe development influenced by cellular latecomers, study finds By
Laurel Hamers
2:18pm, October 6, 2016
Baby humans’ brain cells take awhile to get situated after birth, it turns out. A large group of young nerve cells moves into the frontal lobe during infants’ first few months of life, scientists report in the Oct. 7 Science. The mass migration might help explain how human babies’ brains remain so malleable for a window of time after birth.
Most of the brain’s nerve cells, or neurons, move to their places in the frontal lobe before birth. Then, as babies interact with the world, the neurons link together into circuits controlling learning, memory and social behavior. Those circuits are highly malleable in early infancy: Connections between neurons are formed and severed repeatedly. The arrival of new neurons during the first few months of life could help account for the circuits’ prolonged flexibility in babies, says study coauthor Eric Huang, a neuropathologist at the University of California, San Francisco.
“The fact that [the neurons] are migrating for months and months is remarkable,” says Stephen Noctor, a neuroscientist at the University of California, Davis who wasn’t involved in the work.
Huang and colleagues noticed a group of cells making proteins related to migration when looking at slices of postmortem infant brains under an electron microscope. To catch these neurons in the act of moving, though, the team used rare samples of brain tissue collected and donated immediately after infants’ deaths. The team infected those tissues with a virus tagged with a glowing protein. When the virus infected the brain cells, they glowed green. Then the researchers could track the migrating neurons’ path across the brain.
Nerve cells on the move
A group of neurons (shown in green) starts out in the subventricular zone (SVZ) and migrates outward in an arc towards the surface of the frontal lobe. Some of them also cluster around blood vessels (shown in red).

The neurons started as a cluster in the subventricular zone, a layer inside the brain where new neurons are born, and then formed a chain moving into the frontal lobe, Huang’s team found. Once the migrating neurons settled down later in development, they mostly became inhibitory interneurons. This type of neuron acts like a stoplight for other neurons, keeping signaling in check.
Huang’s team found migrating neurons in the brains of babies up to about seven months old, with migration peaking around 1.5 months and then tapering off.
“In the first six months, that’s kind of [infants’] critical period when they slowly develop their response to [their] environment. They start to engage with emotions,” says Huang. “Our results provide a cellular basis for postnatal human brain development and how cognition might be developed.”
By replenishing the frontal lobe’s supply of building blocks midway through construction, the new neurons might help babies’ brain circuits stay malleable longer. The mass migration after birth means that experiences in infancy could affect where these neurons end up — and, by extension, the connections they form.

English to French: from manufacturer's information on the drug "Solian"General field: MedicalDetailed field: Medical: Pharmaceuticals

Source text - English4.4 Special warnings and precautions for use
As with other neuroleptics, Neuroleptic Malignant Syndrome, characterized by hyperthermia, muscle rigidity, autonomic instability, altered consciousness and elevated CPK, may occur. In the event of hyperthermia, particularly with high daily doses, all antipsychotic drugs including Solian should be discontinued.
Solian is eliminated by the renal route. In cases of severe renal insufficiency, the dose should be decreased and intermittent treatment should be considered (see 4.2 Posology and method of administration).
Solian may lower the seizure threshold. Therefore patients with a history of epilepsy should be closely monitored during Solian therapy.
In elderly patients, Solian, like other neuroleptics, should be used with particular caution because of a possible risk of hypotension or sedation.
As with other antidopaminergic agents, caution should be also exercised when prescribing Solian to patients with Parkinson's disease since it may cause worsening of the disease. Solian should be used only if neuroleptic treatment cannot be avoided.
Acute withdrawal symptoms including nausea, vomiting and insomnia have very rarely been described after abrupt cessation of high doses of antipsychotic drugs. Recurrence of psychotic symptoms may also occur, and the emergence of involuntary movement disorders (such as akathisia, dystonia and dyskinesia) has been reported. Therefore, gradual withdrawal is advisable.
Prolongation of the QT interval
Amisulpride induces a dose-dependent prolongation of the QT interval. This effect, known to potentiate the risk of serious ventricular arrhythmias such as torsades de pointes is enhanced by the pre-existence of bradycardia, hypokalaemia, congenital or acquired long QT interval. Hypokalaemia should be corrected.
Before any administration, and if possible according to the patient's clinical status, it is recommended to monitor factors which could favour the occurrence of this rhythm disorder:
-bradycardia less than 55 bpm,
- hypokalaemia,
-congenital prolongation of the QT interval.
-on-going treatment with a medication likely to produce pronounced bradycardia (< 55 bpm), hypokalaemia, decreased intracardiac conduction, or prolongation of the QTc interval (see 4.5 Interaction with other medicinal products and other forms of interaction).

Source text - EnglishExtract from an article entitled “Measuring Biodiversity Value” published on the London National History Musem website.

Biodiversity value in theory:
identifying a fundamental currency of value to people

Biodiversity has been seen as the total (and irreducible) complexity of all life, including not only the great variety of organisms but also their varying behaviour and interactions. From this viewpoint, no single objective measure of biodiversity is possible, only measures relating to particular purposes or applications. So for conservationists, for example, a measure of biodiversity should quantify a value that is both broadly shared among the people for whom they are acting and considered as being in need of protection.

One of the more broadly shared and economically defensible values for conserving wholesale biodiversity (rather than just the few components or 'biospecifics' with obvious high use value at present) may be seen to lie in ensuring continued possibilities both for adaptation, and for future use by people in a changing and uncertain world (this is not to deny other possible values). Consequently, biologists have argued that this value in biodiversity is likely to be associated with the variety of different genes that can be expressed by organisms as potentially useful phenotypic traits or characters (different chemicals, morphological features, functional behaviour). Because we do not know yet precisely which genes or characters will be of value in the future, first they must all be treated as having equal value, and second, the greatest value for conservation will come from ensuring the persistence of as many different genes or characters as possible, as a form of insurance (ref 2, ref 3).

For example, a dandelion and a giant redwood can be seen to represent a richer collection of characters in total, and so greater diversity value, than another pair of more similar species, a dandelion and a daisy (ref 1). This shows how the phenotypic characters (or the genes that code for them) could provide a 'currency' of value for biodiversity. Pursuing this idea, we will then need to maximise richness in the character currency within the conservationists' 'bank' of managed or protected areas.

A consequence of this approach to valuing biodiversity is that it provides one possible unified view of the traditional three levels at which biodiversity has been described. In effect it uses genetic diversity as a basis for valuing both species diversity (for their relative richness in different genes) and ecosystem diversity (for the relative richness in the different processes to which the genes ultimately contribute). This provides additional justification for multi-level approaches and biodiversity-surrogate methods.

A particular strength of the single currency approach is that it avoids the problems in compound measures of trying to trade-off measures for different properties that really cannot be compared or inter-converted (such as species richness and the relative abundances among species that are combined in the diversity measures used in community ecology), which otherwise can lead to confusion and a loss of accountability. This advantage of accountability in terms of a single currency of value becomes particularly important when faced with the problem of choosing areas for biodiversity conservation, when many other factors may be involved (see the sequential approach to accommodating multiple factors).

I am a Qualified Translator, truly passionate about languages, who holds a Master's Degree in Linguistics and a Professional Certificate in Scientific Translation. With a Doctorate Degree in Pharmacy and years of professional experience, I pride myself in the breadth of knowledge I have in Biomedical and Life Sciences related fields.